Electric drill



W. B. ENGELHARDT.

ELECTRIC DRILL.

APPLICATION FILED SEPT 9, I920.

1,%3%,2@2 Pmented Oct. 311, 11922.

2 SHEETS-SHEE1 l.

W. B. ENGELHARDT.

ELECTRIC DRILL.

APPLICATION FILED SEPT. 9. I920.

1,,4L84,22 Patented Oct. 31, 1922.

2 SHEETS-SHEE1 2.

Patented (lot. 31, 1922.

r 1 a re v s ini alised i ritatin WILLIAIVI B. ENGELHARDT, OF GHICAGO, ILLINOIS.

ELECTRIC DRILL.

Application filed September 9, 192.0.

To all whom it may concern:

Be it known that 1, WILLIAM B. Enenn I-IARDT, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful improvements in Electric Drills, of which the following is a specification.

My invention relates to electric drills, and has for its object the provision of means for conveniently changing the speed of the driven drill shaft.

A further object of the invention is the provision of means to permit the motor to run while the driven drill shaft is standing still.

A further object of the invention is the provision of means for holding the several gears in operative engagement.

A still further object of the invention is the provision of means for holding the shifting gear in neutral position.

A still further object of the invention is the provision of a double, or two point hearing for the driven drill shaft.

With the above and other objects in view, the invention consists in the novel features of construction, arrangement and combination of parts hereinafter described and finally pointed out in the claim hereto appended.

Referring to the accompanying drawings forming a part of this specification where in like characters of reference denote similar parts throughout the several views:

Fig. 1, is a view taken on'line 1-1 of Fig. 2, showing the shifting lever and idle gear in neutral position.

Fig. 2, is a side elevation of the lower end of an electric drill embodying my invention.

Fi 3, is a View similar to Fig. 1, showing die idle shifting gear in mesh with a selected driven drill shaft gear.

Fig. 4:, is a view partly in elevation and partly in section showing drill shaft speed changing mechanism in accordance with my invention.

Referring to the drawings, the reference character 1 indicates the motor casing of an electric drill. 2 indicates the armature shaft, 3 a suitable armature, and a a fan member which is lined to the armature shaft below the armature 3.

indicates a gear casing whirh arranged below the motor casing 1 and divided Serial No. 409,282.

therefrom by means of the removable top, or partition 6.

The lower end of the armature shaft 2 is journaled in a suitable bearing 7. The hub S of the fan 1 is journaled in the central opening 9 of the top plate, or partition (3, as shown in Fig. a. in carrying out the aim of my present invention, I employ a suitable ear 10 which is movable longitudinally upon the armature shaft 2. The armature shaft 2 is provided with a longitudinal key-way 11 to receive a key 12 which is suitable fixed to the gear 10.

The gear 10 is held between the yoked end 13 of a suitable shifting lever 1-1. The yoked end 13 is provided with openings 15 through which the armature shaft passes to permit the lever to be shifted in an arcuate path.

An idle gear 16 is also rotatably supported between the yoked end 13 of the shifting lever A. The idle gear 16 meshes with the longitudinally movable armature shaft gear 10, as shown in Figs. 1 and 3.

17 indicates a driven drill shaft positioned a suitable distance from the armature, or drive shaft and the lower end thereof is journaled in a suitable bearing 18, while the upper end thereof is journaled in the hearing 19 carried by the removable partition 6. The lower end of the shaft 17 is provided with a ball race 20 for engaging with the ball bearings 21. 22 indicates a suitable ball bearing cup member carried by the lower end of bearing 19 which forms apart of the gear casing.

The upper end of the driven drill shaft 17 is provided with a plurality of fixed gears designated 23, 2a, 25 and 26, said gears each being of a different diameter, as clearly shown in Figs. 1 and 3.

The shifting lever 14: is normally held in its neutral position, as shown in Figs. 1 and 3, by means of a suitable coiled spring 27, or its equivalent.

The outer end of the shifting lever 1 1 is provided with a locking member consisting of a rod 28 having a head 29 receivable in the outer end of the shifting lever. A coiled spring 30 encircles the rod 28 for normally holding the rod 28 in its innermost position. An L-shaped arm 31 is fixed to the outer end to the rod 27 engage in one of the lock sockets 32, 33, 34.-

or depending upon What drill shaft gear the shifting gear is in mesh with for locking the gears in mesh.

To shift gears, for changing the speed of the driven drill shaft, the operator first withdraws the kicking arm from its engage ing lock socket so that the shifting lever can be moved to its neutral position, if not already there, then the shifting lever is raised or lowered, as desired in the seat, or passage 36 and moved arcuately in the selected horizontal slot 37, 38, 3 9, or lO so that the idle gear can'he moved into mesh with the selected drill. sha'tt gear, as is manifest.

It is evident from the foregoing description that l. provide a simple and practical means for readily changing the speed of the driven drill shaft.

The many advantages ol'' the herein de scribed invention will readily suggest themselves to those skilled in the art to which it appertains.

I do not desire to be understood as limiting myself to the exact details of construction and arrangement as herein described and illustrated, as it is manifest thatvariations and modifications may be made witln out departing from the spirit and scope of my invention and the terms of the following claims, hence I wish it to be understood that I reserve the right to make any such changes, or modifications as may fairly fall within the scope of the appended claim when fairly construed.

1 ,lBd 202 What I claim is:

In anelectric drill, the combination or a casing having a plurality of slotted openings open at one end, a partition for said casing, an armature drive shaft journaled within said casing, a driven drill shaft journaled Within said casing adjacent said drive shaft and running parallel therewith, a shifting lever having a yoked end pivotally and slidably connected at its inner end to the armature drive shaft, a gear positioned between the yoked end of the shifting lever and slidably mounted upon the armature drive shaft, an idle gear rotatably supported between the yoked end of the shifting lever adapted to mesh with S id drive shaft gear, a series of change speed gears fixed to said driven drill shaft, said idlegear being capable otli movement in an arcuate path to mesh with a selected change speed gear through swinging movement of said shifting lever, an L-shaped locking member yieldingly held in its innermost position at the outer end of said shifting lever, said casing being provided with a plurality of sockets adjacent the slotted openings in the casing to receive the free, end of said locking member for holding the idle gear in mesh with its selected change speed gear and resilient means connecting the shitting lever with the casing for normally holding the idle gear in a neutral position. In testimony whereof, I have hereunto signed my name to the specification.

WILLIAM B. iinenmiannrj 

